Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Triangulum Pinwheel: 07-10 (45), 07-11 (45), 07-09 (43), 07-08 (42), 07-07 (40) — by astronomy; check the weather when the night is within four days.

2041-06-20astronomy score per night — click a bar for that night2041-07-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-06-20 Thu	7	—	unknown	03:00–03:40 (marginal, 0.67 h)	79.2° 09:00	4.42	52%	42.3°
2041-06-21 Fri	8	—	unknown	03:00–03:40 (marginal, 0.67 h)	79.2° 08:55	4.42	41%	31.0°
2041-06-22 Sat	11	—	unknown	03:35–03:40 (good, 0.08 h)	79.2° 08:50	4.43	30%	22.6°
2041-06-23 Sun	14	—	unknown	03:25–03:40 (good, 0.25 h)	79.2° 08:45	4.43	21%	20.6°
2041-06-24 Mon	17	—	unknown	03:15–03:40 (good, 0.42 h)	79.2° 08:40	4.44	13%	26.1°
2041-06-25 Tue	21	—	unknown	03:10–03:40 (good, 0.5 h)	79.2° 08:40	4.45	7%	35.6°
2041-06-26 Wed	22	—	unknown	03:05–03:40 (good, 0.58 h)	79.2° 08:35	4.46	2%	46.5°
2041-06-27 Thu	23	—	unknown	03:05–03:40 (good, 0.58 h)	79.2° 08:30	4.47	0%	57.9°
2041-06-28 Fri	25	—	unknown	03:00–03:40 (good, 0.67 h)	79.2° 08:25	4.49	0%	69.4°
2041-06-29 Sat	26	—	unknown	02:55–03:40 (good, 0.75 h)	79.2° 08:25	4.5	2%	80.9°
2041-06-30 Sun	29	—	unknown	02:50–03:45 (good, 0.92 h)	79.2° 08:20	4.52	6%	92.2°
2041-07-01 Mon	30	—	unknown	02:45–03:45 (good, 1.0 h)	79.2° 08:15	4.55	11%	103.4°
2041-07-02 Tue	31	—	unknown	02:45–03:45 (good, 1.0 h)	79.2° 08:10	4.57	18%	114.5°
2041-07-03 Wed	33	—	unknown	02:40–03:45 (good, 1.08 h)	79.2° 08:05	4.59	26%	125.3°
2041-07-04 Thu	35	—	unknown	02:35–03:45 (good, 1.17 h)	79.2° 08:05	4.62	34%	135.9°
2041-07-05 Fri	37	—	unknown	02:30–03:50 (good, 1.33 h)	79.2° 08:00	4.65	44%	145.8°
2041-07-06 Sat	39	—	unknown	02:30–03:50 (good, 1.33 h)	79.2° 07:55	4.68	53%	154.4°
2041-07-07 Sun	40	—	unknown	02:25–03:50 (good, 1.42 h)	79.2° 07:50	4.71	63%	159.5°
2041-07-08 Mon	42	—	unknown	02:20–03:50 (good, 1.5 h)	79.2° 07:45	4.74	73%	158.0°
2041-07-09 Tue	43	—	unknown	02:20–03:50 (good, 1.5 h)	79.2° 07:45	4.78	82%	150.4°
2041-07-10 Wed	45	—	unknown	02:20–03:55 (good, 1.58 h)	79.2° 07:40	4.81	89%	139.6°
2041-07-11 Thu	45	—	unknown	02:15–03:55 (good, 1.67 h)	79.2° 07:35	4.85	95%	127.3°
2041-07-12 Fri	40	—	unknown	02:15–03:55 (good, 1.67 h)	79.2° 07:30	4.89	99%	114.1°
2041-07-13 Sat	34	—	unknown	02:20–03:55 (good, 1.58 h)	79.2° 07:30	4.93	100%	100.4°
2041-07-14 Sun	29	—	unknown	02:50–04:00 (good, 1.17 h)	79.2° 07:25	4.97	98%	86.4°
2041-07-15 Mon	25	—	unknown	03:55–04:00 (good, 0.08 h)	79.2° 07:20	5.01	93%	72.4°
2041-07-16 Tue	22	—	unknown	01:30–04:00 (marginal, 2.5 h)	79.2° 07:15	5.06	86%	58.6°
2041-07-17 Wed	21	—	unknown	01:25–04:05 (marginal, 2.67 h)	79.2° 07:10	5.1	77%	45.5°
2041-07-18 Thu	23	—	unknown	01:15–04:05 (marginal, 2.83 h)	79.2° 07:10	5.15	66%	33.4°
2041-07-19 Fri	29	—	unknown	03:30–04:05 (good, 0.58 h)	79.2° 07:05	5.19	55%	23.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-06-20&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.